實(shí)體： article、category
article 多 對(duì) category 一 關(guān)系 article 有 category_id 外鍵
傳json參數(shù)類型到action,article里面的屬性都映射上了,而category對(duì)象為null
是什么技術(shù)讓article可以映射上的？為什么article.category卻沒映射上呢？謝謝回答，麻煩了！

action

 public RespResult insert(@RequestBody Article article)

ajax 提交的json參數(shù)

{
    "category.id": "4",
    "name": "123",
    "author": "",
    "source": "",
    "sort": "",
    "createDate": "",
    "content": "<p>123</p>"
}

實(shí)體

 public class Article extends BaseEntity{

    private static final long serialVersionUID = 1L;

    private String name;    
    private Category category;
        public Category getCategory() {
        return category;
    }
    public void setCategory(Category category) {
        this.category = category;
    }
}